Electronically driven collapse of the bulk modulus in δ-plutonium.

ABSTRACT: Plutonium metal exhibits an anomalously large softening of its bulk modulus at elevated temperatures that is made all the more extraordinary by the finding that it occurs irrespective of whether the thermal expansion coefficient is positive, negative, or zero-representing an extreme departure from conventional Grüneisen scaling. We show here that the cause of this softening is the compressibility of plutonium's thermally excited electronic configurations, which has thus far not been considered in thermodynamic models. We show that when compressible electronic configurations are thermally activated, they invariably give rise to a softening of the bulk modulus regardless of the sign of their contribution to the thermal expansion. The electronically driven softening of the bulk modulus is sho

SUBMITTER: Harrison N 

PROVIDER: S-EPMC7060724 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature